Notification indicative of a change in efficacy of therapy

Abstract

In some examples, a processor is configured determine whether efficacy of therapy delivered by a medical device to the patient may have changed and generate a notification based on the determination. For example, a processor may be configured to determine whether a bioelectrical brain signal indicative of activity of a brain of a patient includes a biomarker that indicates efficacy of therapy delivered by a medical device to the patient may have changed, and generate notification based on determining the bioelectrical brain signal includes the biomarker. In some examples, the processor modifies the therapy delivered to the patient prior to generating the notification.

What is claimed is: 
     
         1 . A method comprising:
 receiving, with one or more processors, information representative of a bioelectrical brain signal of a patient;   determining, with the one or more processors, whether the bioelectrical brain signal includes a biomarker that indicates efficacy of therapy delivered by a medical device to the patient may have changed; and   generating, with the one or more processors, a notification based on determining the bioelectrical brain signal includes the biomarker.   
     
     
         2 . The method of  claim 1 , wherein receiving the bioelectrical brain signal comprises receiving, with the one or more processors, the bioelectrical brain signal from a sensing module at periodic, predetermined, or random intervals. 
     
     
         3 . The method of  claim 1 , wherein receiving the bioelectrical brain signal comprises:
 receiving, with the one or more processors, user input; and   receiving, with the one or more processors, the bioelectrical brain signal from a sensing module in response to receiving the user input.   
     
     
         4 . The method of  claim 1 , wherein determining whether the bioelectrical brain signal includes the biomarker comprises comparing an amplitude of the bioelectrical brain signal to a threshold value. 
     
     
         5 . The method of  claim 1 , wherein the bioelectrical brain signal comprises a sensed bioelectrical brain signal, and wherein determining whether the sensed bioelectrical brain signal includes the biomarker comprises comparing the sensed bioelectrical brain signal to a baseline bioelectrical brain signal. 
     
     
         6 . The method of  claim 1 , wherein determining whether the bioelectrical brain signal includes the biomarker comprises comparing a first signal strength in at least one frequency band of the bioelectrical brain signal to a second signal strength in the at least one frequency band of the baseline bioelectrical brain signal. 
     
     
         7 . The method of  claim 1 , wherein determining whether the bioelectrical brain signal includes the biomarker comprises:
 comparing a first power level in a beta band of the sensed bioelectrical brain signal with a second power level in the beta band of the baseline bioelectrical brain signal; and   comparing a third power level in a gamma band of the sensed bioelectrical brain signal with a fourth power level in the gamma band of the baseline bioelectrical brain signal,   wherein generating the notification comprises generating the notification in response to determining the first power level in the beta band of the sensed bioelectrical brain signal is greater than the second power level in the beta band of the baseline bioelectrical brain signal and the third power level in the gamma band of the sensed bioelectrical brain signal is less than the fourth power level in the gamma band of the baseline bioelectrical brain signal.   
     
     
         8 . The method of  claim 1 , wherein generating the notification comprises generating at least one of a visible message, an audible signal or a somatosensory notification. 
     
     
         9 . The method of  claim 1 , further comprising, prior to generating the notification, determining whether a confidence in the bioelectrical brain signal is greater than or equal to a confidence threshold, wherein determining whether the bioelectrical brain signal includes the biomarker comprises determining whether the bioelectrical brain signal includes the biomarker in response to determining the confidence in the bioelectrical brain signal is greater than or equal to the confidence threshold. 
     
     
         10 . The method of  claim 9 , wherein determining whether the confidence in the bioelectrical brain signal is greater than or equal to a confidence threshold comprises comparing at least one of consistency of the measured signal, a signal strength, and a background noise level to a predetermined threshold value. 
     
     
         11 . The method of  claim 9 , wherein the bioelectrical brain signal comprises a first bioelectrical brain signal and the confidence comprises a first confidence, the method further comprising:
 in response to determining the first confidence in the first bioelectrical brain signal is not greater than or equal to the confidence threshold, incrementing a counter;   after incrementing the counter, determining whether a value of the counter is greater than or equal to a counter threshold;   in response to determining the value of the counter is less than the counter threshold, determining whether a second confidence in a second bioelectrical brain signal sensed after the first bioelectrical brain signal is greater than or equal to the confidence threshold; and   in response to determining the value of the counter is greater than or equal to the counter threshold, at least one of controlling the medical device to revert to a safe mode or generating the notification.   
     
     
         12 . The method of  claim 1 , further comprising:
 receiving a baseline bioelectrical brain signal;   selecting a signal characteristic of the baseline bioelectrical brain signal;   determining a tolerance range for the signal characteristic; and   determining the biomarker based on the signal characteristic of the baseline bioelectrical brain signal and the tolerance range.   
     
     
         13 . The method of  claim 1 , wherein the bioelectrical brain signal comprises a first bioelectrical brain signal, the method further comprising:
 prior to generating the notification and in response to determining the first bioelectrical brain signal includes the biomarker, modifying the therapy delivered by the medical device, wherein modifying the therapy generates a modified therapy;   controlling the medical device to deliver the modified therapy to the patient; and   determining, with the one or more processors, whether a second bioelectrical brain signal sensed after the medical device delivered the modified therapy to the patient includes the biomarker, wherein generating the notification comprises generating the notification in response to determining the second bioelectrical brain signal includes the biomarker.   
     
     
         14 . The method of  claim 13 , wherein modifying the therapy delivered by the medical device comprises modifying at least one therapy parameter value with which the medical device generates and delivers therapy to the patient. 
     
     
         15 . The method of  claim 1 , wherein the bioelectrical brain signal comprises a first bioelectrical brain signal, the method further comprising:
 prior to generating the notification and in response to determining the first bioelectrical brain signal include the biomarker, modifying the therapy delivered by the medical device, wherein modifying the therapy generates a modified therapy;   prior to or after modifying the therapy, incrementing a counter that indicates a number of therapy modification attempts;   controlling the medical device to deliver the modified therapy to the patient;   determining, with the one or more processors, whether a second bioelectrical brain signal sensed after the medical device delivered the modified therapy to the patient includes the biomarker;   in response to determining the second bioelectrical brain signal includes the biomarker, determining whether a value of the counter is greater than or equal to a counter threshold;   in response to determining the value of the counter less than the counter threshold, modifying the modified therapy delivered by the medical device; and   in response to determining the value of the counter greater than or equal to the counter threshold, at least one of controlling the medical device to revert to a safe mode or generating the notification.   
     
     
         16 . The method of  claim 1 , further comprising determining at least one of a number of episodes or a frequency of episodes experienced by the patient, wherein generating the notification comprises generating the notification in response to determining the bioelectrical brain signal includes the biomarker and the at least one of the number of episodes or the frequency of episodes experienced by the patient is greater than or equal to an episode threshold. 
     
     
         17 . A system comprising:
 a sensing module configured to sense a bioelectrical brain signal of a patient; and   one or more processors configured to determine whether the bioelectrical brain signal includes a biomarker that indicates efficacy of therapy delivered by a medical device to the patient may have changed, and generate notification based on determining the bioelectrical brain signal includes the biomarker.   
     
     
         18 . The system of  claim 17 , wherein the one or more processors are configured to receive the bioelectrical brain signal from the sensing module at periodic, predetermined, or random intervals. 
     
     
         19 . The system of  claim 17 , further comprising a user interface, wherein the one or more processors are configured to receive the bioelectrical brain signal from a sensing module in response to receiving user input via the user interface. 
     
     
         20 . The system of  claim 17 , wherein the one or more processors are configured to determine whether the bioelectrical brain signal includes the biomarker by at least comparing an amplitude of the bioelectrical brain signal to a threshold value.